Furnace-grate



m. 6l9,494. Patented Feb. I4, I899;

T..E. MARTIN.

FURNACE GBATE.

[Application filed Juna'23, 1897.1

4 Sheets-Sheet (No Model.)

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;T. E. MARTIN. Y FURNACE GRATE.

Application filed June 23, 1897.- (No Model.) 4 Sh'eeis--Shet 2 Wain/96 89 6 IWZ/flficr I W 122% m pm; 0am. I 6y fiww ay m: uonms PETERS co. moruumo" wuuma'ron n. c.

Patented Feb. l4, I899. v

T.- E. MARTIN.

FURNACE GRATE.

' on filed June 23,.1897.)

No. Bl9,494.

No Model.)

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(Application filed Jgne 23, 1897.: (No Model.) I 4 Sheets-She'ef 4.

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NlTED STATES THOMAS E. MARTIN, OF CHICAGO, ILLINOIS.

FU RNAC E-G RATE.

SPECIFICATION forming part of Letters Patent No. 619,494, dated February 14, 1899. Application filed June 23, 1897- Serial No. 641,853- (No model.)

T0 00% whom, it may concern:

Be it known that I, THOMAS E. MARTIN, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Furnace-Grates, of which the following is a specification.

One of the objects of my invention is to provide such a construction and arrangement of longitudinally-extended grate-bars that when rocked they do not break the surface of the fire, but act only on the lower portion or strata of the fuel, loosening up and removing the ashes and fine cinders without mixing the incandescent fuel therewith and without projecting into such fuel so as to be burned, thus saving fuel and lengthening the life of the bars.

Another object is to so construct and control such rocking grate-bars that they may be raked from end to end by an ordinary scraper.

A further object is to provide means whereby the resistanceincident to the operation of the grate under the described arrangement is materially reduced and minimized.

Still other objects and features of the invention will be understood fromthe ensuing description and pointed out in the claims, reference being had to the accompanying drawings, in which- Figure l is a perspective view of the complete grate. Fig. 2 is a plan View of the same. Fig. 3 is a detail plan view of one of the grate-bars. Fig. t is a side view of the same. Fig. 5 is an end View of the same. Fig. 6 is a section of the same on the line a a of Fig. 4.. Fig. 7 is a detail View of a portion of one of the bearing-bars. Fig. 8 is a cross-section through said bar on the line b b of Fig. 7. Fig. 9 is a plan view of said bearing-bar. Fig. 10 is a detail plan view of the bearingbar located at the front of the furnace. Fig. 11 is a detail cross-sectional view on the line 01 d of Fig. 10. Fig. 12 is an enlarged detail cross-section through the grate, the dotted lines showing the position of the grate-bars when rocked. Fig. 13 is a detail view of the shaker bar or shaft.

In carrying out my invention I provide a grate consisting of bars so longitudinally arranged and constructed as topermit ready and convenient cleaning of the body of fuel by raking or scraping with a suitable instrument in the ordinary manner. These bars are also of such construction and arrangement as to act upon the lower strata of the fuel alone, as stated, with the results outlined, dispensing with projections extending into the fuel, which projections are apt to be burned or injured by the heat and which also cause clogging when shaking or raking, catch the edge of the scraper, and interfere with the rapid cleaning of the grate.

Referring to Fig. 1, the grate-bars are designated generally at A, and of these there may be several sets, according to the size of the furnace or length of its fire-box, all the bars of a set being arranged lengthwise of the furnace and the sets being supported. upon transverse bearing-bars, as shown, and in the construction contemplated, especially when there is a plurality of sets and consequently one or more intermediate bearingbars, it is proposed that the upper edges of the bearing-bars, certainly of the intermediate bars, shall at all times be flush with an upper longitudinally-extending surface of each grate-bar whatever the position said bars may have assumed in rocking between the definite limits at which they are stayed, as hereinafter explained.

Each grate-bar consists of a longitudinal Web 25, having formed at its upper part at each end a head 26, undercut concaved at an acute angle to rest upon a knife-edge pivot to be described. At each side of the web, slightly below its straight crest, the bar is extended laterally to equal distances from its longitudinal center, these lateral extensions being curved and sloping away from the web and being shown in the form of teeth 27, described, as to their upper edges, upon curves about concentric with the rocking axis of the bar and having the sides gradually cut away, as in Fig. 6, without a rounded angle at the junction between said sides and the upper edges, thus presenting an outline which does not catch any hard substance and which does not pinch or clog between the gratebars. Extended below the teeth is the leg 28 of the grate-bar, which leg is engaged by the connecting-bar of the shaking apparatus.

The grate-bars A rest by their heads 26 on the knife-edge pivots 29, extending individw ally and separately from the sides of the bearing-bars 39, with open spaces between, so that there shall he no ledge or pocket beneath the pivots. This knife-edge bearing red uces friction and is shielded by the concaved heads of the grate-bars, which provide stops to limit the throw or rock of the bars as the sloping sides of the concavity engage against the sloping sides of the bearing-pivots 29, and these stops will be so calculated that the crests of the longitudinal webs 25 will, as indicated in Fig. 12, never be thrown below the plane of the upper edges of the bearing-bars, with which they are at the outset flush, nor below any part of the teeth or lateral extensions. The bearing-bars extend above the knifeedges to come flush with the crests of the grate-bars and serve as guides and prevent their endwise displacement.

The grate-bars are set side by side, but so that their teeth do not intermesh, and owing to these teeth being of equal length there will always be a straight and unbroken longitudinal interval or space between each grate-bar and its neighbor which may be traversed by the prongs of a rake, if desired, which the fact that the crests of the bars are always flush and uninterrupted, whether or not transverse bearing-bars are used, and always extend above the lateral projections or teeth makes the employment of a cleaning-scraper en tirely feasible and easy. The grate-bars of each set are linked together by the connecting-rods 31, which latter are perforated to receive the legs 23 of said bars, the legs of the outer bars being pivoted to the rods.

The shaker-bar or rock-shaft 32, operated manually or otherwise, extends longitudinally beneath and is yoked with the connecting-rods by the construction as follows: Arms 33 depend froin the shaker-bar 32 and have studs 34, which engage between the arms of the yoke 35, secured to and projecting downward from the connecting-rod 31. The distance from the pivot-point a of the grate-bar to the point where the leg 28 is engaged by the connecting-rod 31, that is above the shaker-bar, is equal to the distance from the center of the shaker-bar 32 to the center of the stud 34, engaging the yoke 35. By this means the foot of the leg 28 moves through the are of a circle equal to the arc of the circle described by the stud 34, substantially parallel therewith for the confined limit of movement. Therefore the distance between the leg 28 and the stud 34 will always be practically the same and there will be no variations in length of lever-arms, no loss of force, no change in resistance, and the full power applied will be economically utilized.

The shaker-bar is borne in a bearing in the front plate of the furnace and in other bearings depending from the transverse bearingbars for the grates. To permit its ready adjustment in line withthe bearing in the front plate and parallel with the grate-bars, the yokes 35 are adj ustably secured to the connecting-rods 31 by means of slots 36 and the bolts 37, and the bearing-blocks 38, beneath the transverse bearing-bars, are also adjustably secured in the same manner to said bearing-bars 39, so that the shaker-bar may be laterally adjusted sufficiently to attain the desired alinement.

The bearing-bars 39, carrying the knifeedge bearings 29, may be secured in place by the means shown in Fig. 1, consisting of a casting 40, having a broad base-plate 41 and rib 42, projecting up from the inner part of said base-plate, the end portion of the baseplate at'43 being set into the wall. The rib 42 is slotted at 44, and the end of the bearing-bar 39 is secured by bolts through the slot 44, permitting expansion and contraction of the bearing-bars to be taken up without reaching the walls of the furnace. By means of this construction the bearing-bars maybe placed in furnaces already built without tearing out the side walls and by simply reserving a track or cutting a slot. The bearingbars can also be renewed without disturbing the side walls.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

1. In a grate for a furnace a plurality of grate-sections arranged end to end longitudinally of the furnace and supported by transverse bearing-bars, each section being composed of a plurality of parallel grate-bars also arranged longitudinally of the furnace and having straight crests extending from end to end with lateral extensions sloping away from both sides thereof, said crests being practicallyfiush with the upper edges of the transverse supporting bars, means for rocking said grate-bars, and stops for limiting the rocking movement of the bars before the crests fall below the plane of the transverse bearing-bars or of the lateral extensions.

2. A grate-bar for a furnace, consisting of a web extending from end to end and straight along its crest and teeth extending equidistantly on each side of the web, the top upper edges of which are rounded and slope away from the crest of the web and the downwardlyprojecting sides of which are gradually increased from the tops, and concaved as they descend.

3. A grate-bar for a furnace, consisting of a web extending from end to end of said bar and straight along its crest, and teeth extending equidistantly on each side of the web, the tops or upper edges of which start slightly beneath the crest and are rounded and sloped away therefrom, and the downwardly-proj ecting sides of which are gradually inourved from the tops and concaved as they descend.

4. A rocking grate-bar for a furnace, and means for mounting the same, consisting essentially of a central web having lateral extensions sloping away from the crest of the web, heads atthe ends of the grate-bar having undercut concave journals, bearing-bars,

and knife-edge bearings projecting independently from the sides of the'bearing-bars so as to leave an uninterrupted space beneath the bearings, the sloping walls of the journals acting as stops in conjunction with the sloping sides of the knife-edges, to stop the bar before the crest falls below the plane of the teeth.

5. A rocking grate-bar for a furnace, and means for mounting the same, consisting of a central web, teeth projecting laterally from each side of the Web, below the plane of its crest and sloping away from said crest, heads at the ends of the grate-bar having undercut concave journals, bearing-bars, and knifeedge bearings projecting independently from the sides of the bearing-bars, so as to leave an uninterrupted space beneath the bearings, the sloping walls of the journals acting as stops in conjunction with the slopingsides of the knife-edges, to stop the bar before the crest falls below the plane of the teeth.

6. A grate and means for operating the same, consisting of a plurality of pivotallymounted grate-bars having depending legs, a connecting-rod extending transversely beneath the grate-bars and engaging the feet of said legs, a rocking shaker-shaft beneath the connecting-rod and parallel with the gratebars, a yoke depending from the connectingrod to a point beneath the rock-shaft, and a depending arm from the shaker-shaft having a lateral stud engaging said yoke, the distance from the pivot-point of the grate-bars to their pointof engagement with the connecting-rod being equal to the distance from the axis of the shaker-shaft to the center of the engaging stud.

7. A grate and means for operating the same, consisting of a plurality of grate-sections arranged end to end and longitudinally of the furnace, a plurality of parallel gratebars in each section, also arranged longitudinally of the furnace, and each having a depending leg, transverse connecting-bars, one to each section, engaging with the feet of said legs, a longitudinally-arranged rocking shaker-shaft extending beneath all of the sections and beneath said connecting-bars,yokes dependingfrom the connecting-bars to points beneath the shaker-shaft, and arms depending from the shaker-shaft and having laterallyprojecting studs engaging with said yokes, the distance between the pivot-points of the grate-bars and their points of engagement with the connecting-rods being equal to the distance from the center of the shakerbar to the center of the engaging stud.

In testimony whereof I affix my signature in presence of two witnesses.

THOMAS E. MARTIN.

Witnesses:

WILLIAM J LIDDY, ARTHUR G. SUTER, 

